We thank Prof. Büttner for his comments on our paper (van Schijndel et al., 2020), which allow us to clarify our work and the tectonic model we proposed for the eastern margin of the Namaqua Sector of the Namaqua Natal Metamorphic Province. The Kaaien Terrane forms a tectonic transition between the Kaapvaal Craton, Rehoboth Province, Kheis belt and the Archeachap Terrane of the Namaqua Sector and forms part of an NW-vergent foreland thrust sequence in the Namaqua Front (e.g. Cornell et al., 2006). The exact tectonic extent of the Kaaien Terrane is still unclear and it has recently been proposed to be part of the newly defined Kheis Terrane (Van Niekerk and Beukes, 2019).

Büttner (2020) states that the tectonic model for the Mesoproterozoic evolution of Namaqua Sector which envisages the collision of multiple exotic terranes after the subduction of multiple oceanic basins (e.g. Miller 2012, and references therein) is outdated and newer tectonic models have been discussed in the literature in recent years. Bial et al. (2015a, 2015b, 2016) and Macey et al. (2018) propose a continental back-arc mobile belt setting to explain the high temperature and low pressure history of several terranes of the Namaqua Sector. For example, Pressure-Temperature time (P-T-t) paths describing the crustal evolution for the Kakamas Terrane by Bial et al. (2015a) suggest along-lasting high-temperature history (>650°C) at pressure not exceeding 5.5 kbar between ∼1350 Ma and <1100 Ma. Similar peak conditions have been found for the Aus in southern Namibia (Diener et al., 2013). This could indicate that the Kakamas Terrane is part of a high-temperature/low pressure continental back-arc (Bial et al., 2015a, 2015b, 2016; and references therein). We suggested a different model for that area, which is more consistent with the ‘outdated’ model.

我们感谢布纳（Büttner）教授对我们论文的评论（van Schijndel et al。，2020），它使我们能够阐明我们的工作以及为纳马夸纳塔尔变质省纳马夸地区东缘提出的构造模型。Kaaien地形在Kaapvaal Craton，Rehoboth省，Kheis带和Namaqua断层的Archeachap地形之间形成了构造过渡，并且形成了Namaqua Front西北前缘前冲冲序列的一部分（eg Cornell等，2006）。Kaaien Terrane的确切构造范围尚不清楚，最近有人提出将其作为新定义的Kheis Terrane的一部分（Van Niekerk and Beukes，2019）。

Büttner（2020）指出，纳马夸地区中古生代演化的构造模型已经过时，并且设想了多个海洋盆地俯冲后多个外来地形的碰撞（例如，Miller 2012，及其中的参考文献），并且在2006年讨论了新的构造模型。近年来的文学。Bial等。（2015a，2015b，2016）和Macey等人。（2018）提出了一个大陆弧后移动带的设置来解释纳马夸地区几个地层的高温和低压历史。例如，Bial等人的压力-温度时间（PTt）路径描述了Kakamas地壳的地壳演化。（2015a）建议在〜1350 Ma和<1100 Ma之间的压力不超过5.5 kbar的情况下持续高温历史（> 650°C）。纳米比亚南部的澳大利亚也发现了类似的高峰条件（Diener等，2013）。这可能表明，Kakamas Terrane是高温/低压大陆后弧的一部分（Bial等，2015a，2015b，2016；以及其中的参考文献）。我们针对该区域提出了一种不同的模型，该模型与“过时的”模型更加一致。